A global positioning system (GPS) is a satellite navigation system in middle earth orbit (MEO). Generally, the GPS has 24 GPS satellites orbiting on six orbital planes in space to perform triangle positioning. Each of the satellites transmits signals to GPS terminals at all times. The signals comprising information such as coordinates, time or other parameters are the key elements for positioning accurately.
An assisted global positioning system (AGPS) has now also been developed. Signals transmitted from a mobile phone base station with signals from conventional GPS satellites are applied to accelerate positioning speed. In an AGPS network, a receiver obtains assistance positioning data by communicating with a server. Therefore, the positioning speed is faster than that of a conventional GPS system while also having a higher efficiency.
At present, a GPS terminal apparatus has to download assistance positioning data via a network in advance. It implies that, with respect to a conventional apparatus capable of downloading assistance positioning data via a network, regardless of whether a mobile phone network or a Wi-Fi network is used, a user has to spend additional fees and time to connect to the network in order to obtain the assistance positioning data. For the majority of GPS apparatuses that are incapable of downloading assistance positioning data via the network, even more time is needed to wait for a cold start.
However, downloading the assistance positioning data via the network has limitations. When signals from the network are too weak or even cannot be obtained, the positioning apparatus is unable to provide stable and reliable positioning information. In addition, boot time may cause further inconvenience. In other words, the foregoing approaches do not necessarily reduce positioning time effectively or increase positioning efficiency.